Madeleine Lamborot

Intraspecific variation in morphology and sexual dimorphism in Liolaemus tenuis (Tropiduridae)

Liolaemus tenuis is a widely distributed arboreal lizard species in central-southern Chile. Although two subspecies, L. t. tenuis and L. t. punctatissimus, have been described based on sexual dimorphism, their characteristic have not been accurately demarcated. Therefore, both traditional and geometric morphometrics were used to study the morphological variation of L. tenuis. Four specific questions were addressed: (1) Does population morphological variation occur along a latitudinal gradient, given its wide geographic distribution in a climactic gradient? (2) Does L. tenuis present sexual dimorphism? (3) In the case of dimorphism, what is the variation along a latitudinal gradient? (4) Are these subspecies morphologically distinguishable? The study was performed in a variety of locations, including the following six bioclimatic regions of Chile: arid mediterranean, semi-arid mediterranean, sub-humid mediterranean, humid mediterranean, per-humid mediterranean, and oceanic with mediterranean influence. Male and female individuals were measured and photographed. Our results suggest sexual dimorphism for all morphological variables analyzed. Geometric data indicate that the eye orbits of the males are more extended than those of the females; this is probably related to territorial defense and/or polygynic mating system. The traditional morphometric approach revealed a difference in individuals from the arid region, whereas the geometric approach revealed a difference in individuals from the oceanic region. Differences in the limits of their distribution ranges seem be related to local factors, such as topography and climatic conditions. Finally, is not possible to recognize distinct subspecies within L. tenuis, and our research concludes that the species consists of one homogenous identity.

Karyotypic variation in Chilean lizards of the genusLiolaemus (Iguanidae)

Most of 12 taxa karyotypes retain 6 pairs of metacentric macrochromosomes (primitive), but show reduced numbers of microchromosomes (2n=34, 32 and 30). Others whow increased diploid numbers due to macrochromosomal fissions (up to 4 fissions, 2n=40). One shows a fission polymorphism.

1,4-benzoxazin-3-one, 2-benzoxazolinone and gallic acid from Calceolaria thyrsiflora graham and their antibacterial activity

Secondary metabolites, DIBOA, HBOA, 7-OH-HBOA, BOA and gallic acid, were isolated and quantified from Calceolaria thyrsiflora Graham, a native medicinal plant of Chile belonging to the Scrophulariaceae family. The highest DIBOA contents were determined in leaves (145 mmol kg-1 dry wt) and flowers (161 mmol kg-1 dry wt). Antibacterial activities of DIBOA, HBOA, BOA, gallic acid and infusions of flowers and leaves were determined. The phytomedicinal properties attributed to C. thyrsiflora Graham could be understood on the basis of its antibacterial activity

Allozyme Divergence in Two Syntopic Liolaemus of the Liolaemus monticola Group (Squamata: Tropiduridae)

Abstract Genetic divergence between two traditionally recognized subspecies, Liolaemus monticola chillanensis and Liolaemus monticola ssp., was assessed by allozymic comparison. Both morphotypes are syntopic and restricted to the mountains of the Cordillera de Chillán. Results of 17 presumptive loci have shown diagnostic alleles at five loci in Esterases and MDHP enzymatic systems. This provides evidence that both morphotypes show strong differences in their genetic structure, and they are independent lineages.

Relationships of the morphological variation in diploids, triploids and mosaics of Liolaemus chiliensis (Sauria: Liolaemidae)

Liolaemus chiliensis , a widely distributed species in Chile, is unique in vertebrates because it presents populations with diploid (2n), triploid (3n) and mosaic (2n/3n) females, and with diploid and mosaic males whose meiosis produces reduced (n) and unreduced (2n) euploid gametes. With the aim of evaluating evolutionary consequences of polyploidy, we analyzed the morphological variability of 103 adults of L. chiliensis from separated geographic areas using both traditional and geometric morphometry in order to visualize shape and size differences in individuals with different ploidy. The results indicated that Liolaemus chiliensis is morphologically variable; a significant effect was observed for the interaction term of the three factors tested: sex, ploidy and locality. From the analysis, females exhibited higher values of axilla groin distance than males. There were also morphological differences in mosaic and triploid organisms with respect to the sympatric and allopatric diploids in the dorsal shape of the head, and the presence of intermediate phenotypes of triploids and mosaic lizards with sympatric males and females associated with the axilla groin distance. Results showed that there are morphological differences between polyploid and diploid organisms with both traditional and geometric approaches, suggesting evolutionary trend to differentiation; future research is needed to assess the underlying ecological and genetic mechanisms related to this phenomenon.

CHEMICAL BASIS FOR THE ANTIMICROBIAL ACTIVITY OF ACETANILIDES

In vitro antimicrobial activity of a series of substituted acetanilides against S. aureus, E. coli and C. albicans were measured at two concentrations, 250 mg/ml and 500 mg/ml. Only the structures substituted with halogens in Ca and electron acceptors in the aromatic ring are bioactive. The results are rationalized in terms of the acid properties of the N-H bond, as calculated using AM1-MO theory